Co-Producing a Tool for Climate Resilience in Milwaukee: A Journey in Urban Systems Research
FEATURE
By Pablo Herreros
Pablo Herreros is a PhD student at Barcelona's Autonomous University (UAB) and the Basque Centre for Climate Change (BC3). He is also a Visiting Scholar and former Research Fellow at the Urban Systems Lab, where his research focuses on interacting with policy-makers and non-governmental organizations to co-create new risk knowledge guiding equitable urban adaptation decisions against climate change.
KEY TAKEAWAYS
USL developed the FHVA tool by partnering with Milwaukee community organizations, combining flood modeling with zip code-level visualizations for equitable stormwater management.
The co-production process, while challenging, yielded tangible results with local journalists and policymakers actively using the tool to address flood risks in vulnerable areas.
The initiative showed that effective urban vulnerability assessments require both quantitative metrics and community knowledge to create meaningful change.
Finding My Place in Urban Systems Research
When I reflect on my path from environmental and forestry engineering to urban systems research, it feels like a winding yet purposeful journey. My fascination with applying ecological concepts to urban environments began during my master’s in urban environmental management at Wageningen University in the Netherlands. Back then, I felt like a misfit—I could not pinpoint anyone else working on the type of urban-environmental intersections that intrigued me. That changed in March 2019 when I discovered the Urban Systems Lab (USL). Their work on urban ecosystem services and climate adaptation through green infrastructure gave me a sense of professional alignment and community. For the first time, I realized I was not alone in envisioning this kind of work.
Pablo Herreros (top) and Luis Ortiz (bottom) working on mapping at the Urban Systems Lab
My work at the Urban Systems Lab began with a project I co-led with Timon McPhearson: “Environmental Justice of Urban Flood Risk and Green Infrastructure Solutions.” Supported by the Kresge Crews Program and in partnership with Groundwork Hudson Valley, the project focused on understanding the environmental justice impacts of climate change-induced flooding on minority and low-income communities, while also assessing social equity in green infrastructure planning to mitigate urban flood risks (read more).
Our conversations revealed a critical gap: a locally-tailored flood vulnerability tool designed with and for communities. This led to an experiment in co-production, where no one enters with predefined solutions, and the process itself becomes a learning experience.
Modeling Flood Risk with a Community Lens
One of the cities studied in the “Environmental Justice of Urban Flood Risk and Green Infrastructure Solutions” initiative is Milwaukee. It culminated in the creation of the Milwaukee Flood-Health Vulnerability Assessment (MFHVA), which exemplifies how urban systems research can drive collaborative, community-focused solutions. MFHVA is a tool designed to identify communities across Milwaukee where urban flooding may disproportionately impact vulnerable populations due to socioeconomic and health conditions. By assessing both flood exposure and social vulnerability, the MFHVA provides critical insights to support community-based advocacy and equitable planning for mitigating flood and health risks–challenges that are becoming increasingly urgent as climate change drives more frequent heavy rain events (learn more).
Figure 1: Overlap between flood exposure and social vulnerability priority areas across Milwaukee
Source: Herreros-Cantis et al, 2024
We embarked on this initiative using advanced hydrodynamic flood simulation tools, thanks to generous access from the creators of city-scale modeling software. This allowed us to move beyond proxies like imperviousness and topography to simulate the actual physics of surface runoff. That level of precision was crucial for assessing extreme precipitation flooding in Milwaukee. At the same time, we drew inspiration from efforts like San Francisco’s Flood Health Vulnerability Index. Their challenges with interpreting a single vulnerability index shaped our approach. Instead of creating one all-encompassing map, we opted for disaggregated data visualizations, allowing users to explore specific dimensions of vulnerability independently.
Another pivotal moment came when presenting prototype maps to Milwaukee Water Commons, an environmental justice organization. They pointed out that census tracts, a common spatial unit for analysis, were not intuitive to most residents. We adjusted the maps to include zip code overlays, making them far more accessible and locally relevant.
Lessons in Co-Production
In addition to the important results of the MFHVA, the co-production process itself played a crucial role. I recently published a paper in which I highlight this: Co-producing research and data visualization for environmental justice advocacy in climate change adaptation: The Milwaukee Flood-Health Vulnerability Assessment. The paper details our co-production process with advocacy groups and healthcare practitioners to develop the MFHVA to identify priority areas for equitable stormwater management, demonstrating how co-production makes vulnerability analyses more accessible and actionable for both policymakers and communities. Collaborating with NGOs, local health professionals, and other stakeholders pushed us to clarify our goals repeatedly. I vividly recall moments of frustration during Zoom calls when someone would ask, “What exactly are we doing here again?” These moments were not setbacks—they were essential for aligning our diverse perspectives.
The result is a tool that belongs as much to the community as it does to the researchers. Local journalists have used it to highlight flood risks in environmental justice communities (1, 2, 3, 4), drawing attention to the potential impact of expanding highways, policymakers and technicians expressed interest in replicating the approach, and other cities have inquired about adapting the methods for their contexts.
Figure 2: Flowchart showing the phases of the co-production process for the MFHVA Source: Herreros-Cantis et al, 2024
Charting a Path Forward
This initiative demonstrated that research rooted in local communities and places can achieve remarkable results. Through direct collaboration with residents, we discovered that practical, on-the-ground work addressing community needs often creates more meaningful change than purely theoretical academic pursuits. What makes co-produced research particularly powerful is how its core approach—deep local engagement and partnership—can be thoughtfully adapted across different settings, from small rural towns to large urban centers, while remaining true to each community's unique character and aspirations.
Through this work, I have seen firsthand how urban systems research can not only advance scientific understanding but also empower communities to adapt to climate challenges. That, to me, is the heart of transformative research.
This initiative opened new doors for me as a researcher. One key realization is that not all valuable knowledge can be quantified as data or mapped. Because of this, quantitative risk analyses may oversimplify a complex landscape of factors that make cities and their communities vulnerable. As I explore alternative ways to analyze urban vulnerability—through complex systems mapping and participatory research processes—I see immense potential for improving decision-making. Ultimately, I am passionate about the idea of testing novel, complementary methodologies that can support co-production processes by integrating the knowledge of different stakeholders, and by facilitating the co-development of shared understandings of vulnerability. This exploration is quite challenging, as it requires me to step outside of my comfort zone (maps and indicators) and dive deep into new philosophies of knowledge linked to qualitative research. Thankfully, my colleagues at the USL, as well as the Basque Centre for Climate Change (BC3) and the Autonomous University of Barcelona (ICTA-UAB) are accompanying me in this journey, providing their vast experience in these new topics.
